THE PROBLEM OF SAND-WATER MANİFESTATİON IN OIL PRODUCTION

Abstract

Sand manifestation has been observed in both deep and shallow wells in areas with abnormally low pressure formations. In all cases, the appearance of sand and water creates complex problems. As a result of the collapse of the bottom whole zone, there are cases of bending and failure of pipelines in and above the filter. All this leads to long repairs. From the development of the well to its subsequent operation a number of processes occur, all of which affect the stability of the rocks weakens and creates conditions for the formation of sand manifestation. As a result of sand movement in the filter area, holes are formed, and the rock, which acts as a support for the operational pipeline, is destroyed and enters the pipeline through the perforated channels. The results of all these processes lead to deformation of the production pipeline, in some cases to the loss of the well. During the development and operation of wells to prevent the destruction of the filter zone and simultaneous sand plugging in the belt, are shown the conditions of the well flow rate. One of the most effective measures against sand-water manifestation is sand plug washing. It has been shown that during washing of sand plugs in production wells, small sand grains are carried out by the flow, but big sand grains sedimentation at the bottom of the well. The distribution of the particles in the flow is carrying out under the force of the earth's gravity at the Bolstmann distribution. It is explain with the increasing of the concentration of particles at the bottom of the well and decreasing at the top of the well. For the first time their hydrodynamic model of sedimentation in suspension has been given by the accepting of the participation of sand particles in the washing at the Bolstmann distribution. İt has been noted that ,although the effective washing of sand plug is an important measures, preventing of formation of sand plug remains as big challenge. After an effective washing of sand plug, it is necessary to applied measures against water manifestation. Otherwise, it is impossible to prevent of sand manifestation. Since high water flow rate (10 ÷ 20 m3/day) gradually destroys the borehole bottom-hole zone and in the filter zone a hole is formed, the wall of the well is destroyed. And this becomes a cause of huge complications. This is because that the water flow cannot destroy the isolation mass,which is applied against water to the layer. Thus, the most effective measure against sand-water manifestation should be consist of three successive integrated measures. Complex measures against sand and water appearance are suggested, which have found application in production. Keywords: well, sand manifestation, sand plug, cement solution, washing process.